It is conventional to feed warm water to the top of a cooling tower and cool the water by air as it passes through the tower. The cooled water is collected in a basin at the bottom of the tower for later use with heat exchange equipment. Frequently the warm water feed contains contaminants such as reaction by-products, soluble and insoluble polymeric compounds, etc. Some contaminants precipitate out of the cooled water and settle in the cooling tower basin. If the contaminants are not removed from the basin, they build up to an unsatisfactory level. Unremoved contaminants entrained in cooled water withdrawn from the basin will foul heat exchange equipment using the cooled water. Fouled heat exchange equipment will have to be taken out of use, disassembled, and cleaned. This results in delay, loss of equipment efficiency and increased maintenance costs.
Various techniques have been employed to remove solids that buildup along the bottom of reservoirs, such as cooling tower basins. U.S. Pat. No. 2,179,249 exemplifies a technique wherein a reservoir is fitted with a perforated pipe system which drains the reservoir extremities. Such designs are inadequate in that solids buildup, block the entrances to the drainage pipes, and prevent removal of substances in the reservoirs.